Bolas' Vengeance

You may only cast a Legendary Sorcery only if
you control a Legendary Creature or
Planeswalker.
Split second
Destroy up to five legendary creatures and/or planeswalkers, you lose life equal to the total creatures and/or planeswalkers destroyed this
way.
When Everest released Bolas from his eternal prison
his only thought was how much would he make them
suffer.